Method of and apparatus for casting



Sept. 8, 1925.

M. C. SPENCER METHOD OF AND APPARATUS FOR CASTING Filed July 16, 1924Fig.3.

Inventor, Millard Cole Spencer,

Patented Sept. 8, 1925,

UNHtiD sTAres arana" o aries.

MILLABD COLE SPENCER, OF EAST ORANGE, NEW JERSEY, ASSIGNOB 'IO' CROCKER-WHEELER COMPANY, OF AMPEBE, "NE-W JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF AND APPARATUS FOR CASTING.

Application filed July 16, 1924. Serial- No. 726,256.

To all whom it may concern:

Be it known that I, MILLARD COLE SPEN- can, a citizen of the UnitedStates of America, and a resident of East Orange, in the county of Essexand State of New Jersey, have invented an Improved Method of andApparatus for Casting, of which the following is a specification.

This invention relates more particularly to the casting of the end ringsfor the sqirrel-cage windings of induction motors. In an induction motorthere is a rotor core of laminated iron disks with a winding formed bycopper bars which pass through circumferentially disposed openings inthe core and project beyond the ends of the core. The projecting endsare joined to metal rings which form good electrical connection betweenthe bars. The bars and rings constitute the squirrel-cage winding.

The object of this invention is to provide an expeditious method andsuitable apparatus for the manufacture of the squirrelcages from bars ofsheet metal and cast 5 rings by which an intimate union between all ofthe bars and the rings is assured.

In the accompanying sheet of drawings which forms a part of thisdescription- Figure 1 is a vertical section through a flask and followboard which is used in connection with this method and apparatus.

Fig. 2 is a vertical section through the apparatus for supporting therotor core and mold while casting.

Fig. 3 is a horizontal section through the apparatus on the lineIII-III.

Fig. 4 is an elevation of a portion of the apparatus for lifting themold.

In practising this method a follow board 10 has placed thereon asuitable pattern 11 for the end-ring of the squirrel-cage, a cylindricalblock 12, and a flask 18, and the flask is rammed with sand. Thecylindrical block is withdrawn, leaving a clearance hole through thesand in the center of the mold, and the flask with the mold is turnedover and placed on a table 14 of a casting apparatus. The follow boardis lifted off and the pattern withdrawn, leaving an open mold for theend-ring.

The table is carried on a tubular column 15 which is mounted to slide ona pedestal 16. The pedestal is hollow and a bushing 17 is held thereinby a set-screw 18 in a properly adjusted position. A rotor core 19, withsquirrel-cage bars 20, 20 set in circumferentially disposed openings,has at its center a shouldered shaft 21. The end of this shaft is passedthrough the clearance hole left in the center of the mold and through ahole in the top of the table which supports the mold and into thebushing by which it is properly centered and supported at the shoulderof the shaft so that the lower ends of the squirrel-cage bars clear thetop of the mold. The mold is then poured and by relative verticalmovement of the sup ports for the rotor core and the mold the lower endsof the squirrel-cage bars are simultaneously plunged into the moltenmetal in the mold. It is not essential which of the supports is moved toeffect their relative movement. As shown, the table which supports themold is lifted. This is effected by a cam 22 on a shaft 23 with a lever24 by which the cam is operated. The ends of the bars are held in placein the poured metal until it has had time to solidify.

I claim,

1. The process of forming a squirrelcage winding which consists inproviding means for supporting squirrel-cage bars disposed substantiallyas elements of a vertical cylinder, and an open mold for an end ring ofthe squirrel-cage supported beneath the bars, pouring molten metal intothe mold, plunging the lower ends of the bars into the metal by relativemovement of the barsupporting means and the mold-supporting means, andholding the bars in such position until the metal has solidified.

2. The process of forming a squirrel-cage winding on the rotor core ofan induction motor which consists in providing squirrelcage bars incircumferentially disposed openings in the core, supporting means forthe core, and an open mold for an end-ring of the squirrel-cagesupported beneath the bars, pouring molten metal into the mold, plungincircumferentially disposed openings in 10 the core, means for supportingan open mold for the end ring beneath the lower ends of the bars, andmeans for effecting relative movement of the core-supporting means andthe inold s'upporting means by which the 15 bars are plunged into themetal.

MILLARD COLE SPENCER;

